• The Journal of Korea Robotics Society
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• v.2 no.4
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• pp.310-316
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• 2007

The paper proposes a human-following behavior of mobile robot and an intelligent space (ISpace) is used in order to achieve these goals. An ISpace is a 3-D environment in which many sensors and intelligent devices are distributed. Mobile robots exist in this space as physical agents providing humans with services. A mobile robot is controlled to track a walking human using distributed intelligent sensors as stably and precisely as possible. The moving objects is assumed to be a point-object and projected onto an image plane to form a geometrical constraint equation that provides position data of the object based on the kinematics of the intelligent space. Uncertainties in the position estimation caused by the point-object assumption are compensated using the Kalman filter. To generate the shortest time trajectory to track the walking human, the linear and angular velocities are estimated and utilized. The computer simulation and experimental results of estimating and trackinging of the walking human with the mobile robot are presented.

• The Journal of Korea Robotics Society
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• v.7 no.2
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• pp.142-149
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• 2012

The camera has limitations of poor visibility in underwater environment due to the limited light source and medium noise of the environment. However, its usefulness in close range has been proved in many studies, especially for navigation. Thus, in this paper, vision-based object detection and tracking techniques using artificial objects for underwater robots have been studied. We employed template matching and mean shift algorithms for the object detection and tracking methods. Also, we propose the weighted correlation coefficient of adaptive threshold -based and color-region-aided approaches to enhance the object detection performance in various illumination conditions. The color information is incorporated into the template matched area and the features of the template are used to robustly calculate correlation coefficients. And the objects are recognized using multi-template matching approach. Finally, the water basin experiments have been conducted to demonstrate the performance of the proposed techniques using an underwater robot platform yShark made by KORDI.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.106-112
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• 1993

A new model for the construction of a sonar map in a specular environment has been developed ad implemented. In a real world where most of the object surfaces are specular ones, a sonar sensor suffers from a multipath effect which results in a wrong interpretation of an objects's location. To reduce this effect and hence to construct a reliable map of a robot's surroundings, a probabilistic approach based on Bayesian reasoning is adopted to both evaluation of object orientations and estimation of an occupancy probability of a cell by an object. The usefulness of this approach is illustrated with the results produced by our mobile robot equipped with ultrasonic sensors.

• The Journal of Korea Robotics Society
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• v.2 no.3
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• pp.255-261
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• 2007

We propose a optimal fusion method for localization of multiple robots utilizing correlation between GPS on each robot in common workspace. Each mobile robot in group collects position data from each odometer and GPS receiver and shares the position data with other robots. Then each robot utilizes position data of other robot for obtaining more precise estimation of own position. Because GPS data errors in common workspace have a close correlation, they contribute to improve localization accuracy of all robots in group. In this paper, we simulate proposed optimal fusion method of odometer and GPS through virtual robots and position data.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.3
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• pp.273-283
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• 2008

This article describes a cooperative localization technique of multiple robots sharing position information of each robot. In case of conventional methods such as EKF, they need to linearization process. Consequently, they are not able to guarantee that their result is range containing true value. In this paper, we propose a method to merge the data of redundant sensors based on constraints propagation techniques on intervals. The proposed method has a merit guaranteeing true value. Especially, we apply the constraints propagation technique fusing wheel encoders, a gyro, and an inexpensive GPS receiver. In addition, we utilize the correlation between GPS data in common workspace to improve localization performance for multiple robots. Simulation results show that proposed method improve considerably localization performance of multiple robots.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.10
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• pp.861-866
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• 2013

This paper presents the development of a racing game by controlling multiple smartphones based on ad hoc communication. The proposed racing game by the smartphone-based control interface does not require any specific game console or remote controller. Thus, any multiple users who have smartphones are able to play the game in a monitor at the same time. In addition, the developed game is applicable to actual mobile robots in cases where the positions of all robots are measured, since its game unit is a mobile robot model with a differential drive. An experimental result shows that the racing game in a PC can be realized by the proposed communication interface through four iPhones based on acceleration sensors.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.1200-1202
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• 2012

미래 전장에서 다수의 지상로봇들이 획득한 표적정보는 원격에 위치한 통제장치로 실시간 전송된다. 통제장치는 정찰영상과 디지털 지도위에 지상로봇들의 현재 동작 상태를 표시한다. 본 논문은 다수의 지상로봇들로부터 동일 표적에 대한 위치 정보가 수신될 경우 이에 대한 융합처리 방안을 제안한다. 이러한 융합처리를 통해 표적위치 정확도를 개선할 수 있으며, 이동 경로 추정을 통해 표적의 초기 탐지시간을 단축할 수 있다.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2411-2413
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• 2004

In this paer, we propose a method to apply a decentralized control algorithm for passive velocity field control using virtual flywheel system to cooperative mobile robots. The considered system convey a common rigid object in a horizontal plain. The effectiveness of proposed control algorithm is examined by numerical simulation for cooperative tasks.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.202-204
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• 2001

가상 세계의 공유 개념은, 특히 사용자들이 인터넷 같이 대규모 네트웍을 통해 지역적으로 분산된 경우는 복제가 수용할 수 있는 상호작용 성능을 제공하기 때문에 각 사용자의 사이트에 정보를 복제함으로써 확장된다. 그러나, 다수의 동시 갱신은 replicas간의 일관되지 않은 뷰를 일으키게 될 것이다. 따라서, 동시성 제어가 복제자들간에 일관된 상태를 유지하도록 하기 위한 중요한 요소가 된다. 우리는 단지 대상 객체의 주변에 있는 사용자들만이 소유권 요청을 다중 전송하게 하는 확장성 있는 예측기반 동시성 제어 스킴을 제안했었다. 이 작업에서, 우리는 모든 사용자들이 동일한 속도론 가지고 가상 세계를 이동한다고 가정했다. 이것은, 그러나, 좀더 사실성을 더하기 위해 사용자가 가상 세계와 상호작용을 할 매 그들의 이동속도를 변경하도록 하는 네트웍 게임같은 네트웍 가상 환경에서는 너무 common 하다. 본 논문은 다양한 속도를 가진 사자를 지원하기 위한 확장을 제안한다. 확장된 스킴은 다른 속도의 수만큼의 다중 Entity Radii를 가지며 각 속도를 가진 사용자에게 분리된 큐를 할당한다. 각 큐는 다음 소유자 후보를 예측하기 위해 동시에 예측을 수행하고 선택된 후보들간에서 최소의 Predicted Collision Time을 가지는 최종 후보자가 선택된다. 이는 사용자의 속도에 기반을 둔 적절한 Entity Radius를 사용함으로써 소유권의 timely advanced transfer과, 다른 이돔 속도와 latency를 가지는 사용자들 간의 간섭을 줄임으로써 공정(공평)한 소유권 양도, 그리고 불필요한 소유권 전송을 줄임으로써 놓은 예측 정확도를 제공한다.성을 지닌 AMMQL 학습법은 로봇축구와 같이 끊임없이 실시간적으로 변화가 일어나는 다중 에이전트 환경에서 특히 높은 효과를 볼 수 있다. 본 논문에서는 AMMQL 학습방법의 개념을 소개하고, 로봇축구 에이전트의 동적 위치 결정을 위한 학습에 어떻게 이 학습방법을 적용할 수 있는지 세부 설계를 제시한다.다.으로서 hemicellulose구조가 polyuronic acid의 형태인 것으로 사료된다. 추출획분의 구성단당은 여러 곡물연구의 보고와 유사하게 glucose, arabinose, xylose 함량이 대체로 높게 나타났다. 점미가 수가용성분에서 goucose대비 용출함량이 고르게 나타나는 경향을 보였고 흑미는 알칼리가용분에서 glucose가 상당량(0.68%) 포함되고 있음을 보여주었고 arabinose(0.68%), xylose(0.05%)도 다른 종류에 비해서 다량 함유한 것으로 나타났다. 흑미는 총식이섬유 함량이 높고 pectic substances, hemicellulose, uronic acid 함량이 높아서 콜레스테롤 저하 등의 효과가 기대되며 고섬유식품으로서 조리 특성 연구가 필요한 것으로 사료된다.리하였다. 얻어진 소견(所見)은 다음과 같았다. 1. 모년령(母年齡), 임신회수(姙娠回數), 임신기간(姙娠其間), 출산시체중등(出産時體重等)의 제요인(諸要因)은 주산기사망(周産基死亡)에 대(對)하여 통계적(統計的)으로 유의(有意)한 영향을 미치고 있어 $25{\sim}29$세(歲)의 연령군에서, 2번째 임신과 2번째의 출산에서 그리고 만삭의 임신 기간에, 출산시체중(出産時體重) $3.50{\sim}3.99kg$사이의 아

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.11
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• pp.1067-1073
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• 2011

In this paper, the methodology of a CA (Control Allocation) based FTNCS (Fault-Tolerant Networked Control System) is proposed. Control allocation is a control surface management technique by redistributing the redundant control surfaces in overactuated systems. In modern high performance aircrafts, they adopt many redundant control surfaces to provide high performance and to satisfy various tactical requirements. Moreover, redundant control surfaces provide an opportunity to compensate performance degradation due to failures in more than one actuator by re-allocating redundant control surfaces. Simulation results with an F-18 HARV demonstrate that the proposed CA based FTNCS can achieve a fast and accurate tracking performance even in the presence of actuator faults.